Changes between Initial Version and Version 1 of TracFastCgi


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Timestamp:
06/27/13 10:44:05 (11 years ago)
Author:
trac
Comment:

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  • TracFastCgi

    v1 v1  
     1[[PageOutline]]
     2
     3= Trac with FastCGI =
     4
     5[http://www.fastcgi.com/ FastCGI] interface allows Trac to remain resident much like with [wiki:TracModPython mod_python] or [wiki:TracModWSGI mod_wsgi]. It is faster than external CGI interfaces which must start a new process for each request.  Additionally, it is supported by much wider variety of web servers.
     6
     7Note that unlike mod_python, FastCGI supports [http://httpd.apache.org/docs/suexec.html Apache SuEXEC], i.e. run with different permissions than web server running with (`mod_wsgi` supports the `WSGIDaemonProcess` with user / group parameters to achieve the same effect).
     8
     9'''Note for Windows:''' Trac's FastCGI does not run under Windows, as Windows does not implement `Socket.fromfd`, which is used by `_fcgi.py`. If you want to connect to IIS, you may want to try [trac:TracOnWindowsIisAjp AJP]/[trac:TracOnWindowsIisAjp ISAPI].
     10
     11[[PageOutline(2-3,Overview,inline)]]
     12
     13
     14== Simple Apache configuration ==
     15
     16There are two FastCGI modules commonly available for Apache: `mod_fastcgi` and
     17`mod_fcgid` (preferred). The latter is more up-to-date.
     18
     19The following sections focus on the FCGI specific setup, see also [wiki:TracModWSGI#ConfiguringAuthentication] for configuring the authentication in Apache.
     20
     21Regardless of which cgi module is used, be sure the web server has executable permissions on the cgi-bin folder. While FastCGI will throw specific permissions errors, mod_fcgid will throw an ambiguous error if this has not been done. (Connection reset by peer: mod_fcgid: error reading data from FastCGI server)
     22
     23=== Set up with `mod_fastcgi` ===
     24`mod_fastcgi` uses `FastCgiIpcDir` and `FastCgiConfig` directives that should be added to an appropriate Apache configuration file:
     25{{{
     26# Enable fastcgi for .fcgi files
     27# (If you're using a distro package for mod_fcgi, something like
     28# this is probably already present)
     29<IfModule mod_fastcgi.c>
     30   AddHandler fastcgi-script .fcgi
     31   FastCgiIpcDir /var/lib/apache2/fastcgi
     32</IfModule>
     33LoadModule fastcgi_module /usr/lib/apache2/modules/mod_fastcgi.so
     34}}}
     35Setting `FastCgiIpcDir` is optional if the default is suitable. Note that the `LoadModule` line must be after the `IfModule` group.
     36
     37Configure `ScriptAlias` or similar options as described in TracCgi, but
     38calling `trac.fcgi` instead of `trac.cgi`.
     39
     40Add the following to the Apache configuration file (below the `FastCgiIpcDir` line) if you intend to set up the `TRAC_ENV` as an overall default:
     41{{{
     42FastCgiConfig -initial-env TRAC_ENV=/path/to/env/trac
     43}}}
     44
     45Alternatively, you can serve multiple Trac projects in a directory by adding this:
     46{{{
     47FastCgiConfig -initial-env TRAC_ENV_PARENT_DIR=/parent/dir/of/projects
     48}}}
     49
     50=== Set up with `mod_fcgid` ===
     51Configure `ScriptAlias` (see TracCgi for details), but call `trac.fcgi`
     52instead of `trac.cgi`. Note that slash at the end - it is important.
     53{{{
     54ScriptAlias /trac /path/to/www/trac/cgi-bin/trac.fcgi/
     55}}}
     56
     57To set up Trac environment for `mod_fcgid` it is necessary to use
     58`DefaultInitEnv` directive. It cannot be used in `Directory` or
     59`Location` context, so if you need to support multiple projects, try
     60alternative environment setup below.
     61
     62{{{
     63DefaultInitEnv TRAC_ENV /path/to/env/trac/
     64}}}
     65
     66=== alternative environment setup ===
     67A better method to specify path to Trac environment is to embed the path
     68into `trac.fcgi` script itself. That doesn't require configuration of server
     69environment variables, works for both FastCgi modules
     70(and for [http://www.lighttpd.net/ lighttpd] and CGI as well):
     71{{{
     72import os
     73os.environ['TRAC_ENV'] = "/path/to/projectenv"
     74}}}
     75or
     76{{{
     77import os
     78os.environ['TRAC_ENV_PARENT_DIR'] = "/path/to/project/parent/dir"
     79}}}
     80
     81With this method different projects can be supported by using different
     82`.fcgi` scripts with different `ScriptAliases`.
     83
     84See [https://coderanger.net/~coderanger/httpd/fcgi_example.conf this fcgid example config] which uses a !ScriptAlias directive with trac.fcgi with a trailing / like this:
     85{{{
     86ScriptAlias / /srv/tracsite/cgi-bin/trac.fcgi/
     87}}}
     88
     89== Simple Cherokee Configuration ==
     90
     91The configuration on Cherokee's side is quite simple. You will only need to know that you can spawn Trac as an SCGI process.
     92You can either start it manually, or better yet, automatically by letting Cherokee spawn the server whenever it is down.
     93First set up an information source in cherokee-admin with a local interpreter.
     94
     95{{{
     96Host:
     97localhost:4433
     98
     99Interpreter:
     100/usr/bin/tracd —single-env —daemonize —protocol=scgi —hostname=localhost —port=4433 /path/to/project/
     101}}}
     102
     103If the port was not reachable, the interpreter command would be launched. Note that, in the definition of the information source, you will have to manually launch the spawner if you use a ''Remote host'' as ''Information source'' instead of a ''Local interpreter''.
     104
     105After doing this, we will just have to create a new rule managed by the SCGI handler to access Trac. It can be created in a new virtual server, trac.example.net for instance, and will only need two rules. The '''default''' one will use the SCGI handler associated to the previously created information source.
     106The second rule will be there to serve the few static files needed to correctly display the Trac interface. Create it as ''Directory rule'' for ''/common'' and just set it to the ''Static files'' handler and with a ''Document root'' that points to the appropriate files: ''$TRAC_LOCAL/htdocs/'' (where $TRAC_LOCAL is a directory defined by the user or the system administrator to place local trac resources).
     107
     108Note:\\
     109If the tracd process fails to start up, and cherokee displays a 503 error page, you might be missing the [http://trac.saddi.com/flup python-flup] package.\\
     110Python-flup is a dependency which provides trac with SCGI capability. You can install it on debian based systems with:
     111{{{
     112sudo apt-get install python-flup
     113}}}
     114
     115
     116== Simple Lighttpd Configuration ==
     117
     118The FastCGI front-end was developed primarily for use with alternative webservers, such as [http://www.lighttpd.net/ lighttpd].
     119
     120lighttpd is a secure, fast, compliant and very flexible web-server that has been optimized for high-performance
     121environments.  It has a very low memory footprint compared to other web servers and takes care of CPU load.
     122
     123For using `trac.fcgi`(prior to 0.11) / fcgi_frontend.py (0.11) with lighttpd add the following to your lighttpd.conf:
     124{{{
     125#var.fcgi_binary="/usr/bin/python /path/to/fcgi_frontend.py" # 0.11 if installed with easy_setup, it is inside the egg directory
     126var.fcgi_binary="/path/to/cgi-bin/trac.fcgi" # 0.10 name of prior fcgi executable
     127fastcgi.server = ("/trac" =>
     128   
     129                   ("trac" =>
     130                     ("socket" => "/tmp/trac-fastcgi.sock",
     131                      "bin-path" => fcgi_binary,
     132                      "check-local" => "disable",
     133                      "bin-environment" =>
     134                        ("TRAC_ENV" => "/path/to/projenv")
     135                     )
     136                   )
     137                 )
     138}}}
     139
     140Note that you will need to add a new entry to `fastcgi.server` for each separate Trac instance that you wish to run. Alternatively, you may use the `TRAC_ENV_PARENT_DIR` variable instead of `TRAC_ENV` as described above,
     141and you may set one of the two in `trac.fcgi` instead of in `lighttpd.conf`
     142using `bin-environment` (as in the section above on Apache configuration).
     143
     144Note that lighttpd has a bug related to 'SCRIPT_NAME' and 'PATH_INFO' when the uri of fastcgi.server is '/' instead of '/trac' in this example (see [trac:#2418]). This should be fixed since lighttpd 1.4.23, and you may need to add `"fix-root-scriptname" => "enable"` as parameter of fastcgi.server.
     145
     146For using two projects with lighttpd add the following to your `lighttpd.conf`:
     147{{{
     148fastcgi.server = ("/first" =>
     149                   ("first" =>
     150                    ("socket" => "/tmp/trac-fastcgi-first.sock",
     151                     "bin-path" => fcgi_binary,
     152                     "check-local" => "disable",
     153                     "bin-environment" =>
     154                       ("TRAC_ENV" => "/path/to/projenv-first")
     155                    )
     156                  ),
     157                  "/second" =>
     158                    ("second" =>
     159                    ("socket" => "/tmp/trac-fastcgi-second.sock",
     160                     "bin-path" => fcgi_binary,
     161                     "check-local" => "disable",
     162                     "bin-environment" =>
     163                       ("TRAC_ENV" => "/path/to/projenv-second")
     164                    )
     165                  )
     166                )
     167}}}
     168Note that field values are different.  If you prefer setting the environment
     169variables in the `.fcgi` scripts, then copy/rename `trac.fcgi`, e.g., to
     170`first.fcgi` and `second.fcgi`, and reference them in the above settings.
     171Note that the above will result in different processes in any event, even
     172if both are running from the same `trac.fcgi` script.
     173
     174{{{
     175#!div class=important
     176'''Note''' It's very important the order on which server.modules are loaded, if mod_auth is not loaded '''BEFORE''' mod_fastcgi, then the server will fail to authenticate the user.
     177}}}
     178
     179For authentication you should enable mod_auth in lighttpd.conf 'server.modules', select auth.backend and auth rules:
     180{{{
     181server.modules              = (
     182...
     183  "mod_auth",
     184...
     185)
     186
     187auth.backend               = "htpasswd"
     188
     189# Separated password files for each project
     190# See "Conditional Configuration" in
     191# http://trac.lighttpd.net/trac/file/branches/lighttpd-merge-1.4.x/doc/configuration.txt
     192
     193$HTTP["url"] =~ "^/first/" {
     194  auth.backend.htpasswd.userfile = "/path/to/projenv-first/htpasswd.htaccess"
     195}
     196$HTTP["url"] =~ "^/second/" {
     197  auth.backend.htpasswd.userfile = "/path/to/projenv-second/htpasswd.htaccess"
     198}
     199
     200# Enable auth on trac URLs, see
     201# http://trac.lighttpd.net/trac/file/branches/lighttpd-merge-1.4.x/doc/authentication.txt
     202
     203auth.require = ("/first/login" =>
     204                ("method"  => "basic",
     205                 "realm"   => "First project",
     206                 "require" => "valid-user"
     207                ),
     208                "/second/login" =>
     209                ("method"  => "basic",
     210                 "realm"   => "Second project",
     211                 "require" => "valid-user"
     212                )
     213               )
     214
     215
     216}}}
     217Note that lighttpd (I use version 1.4.3) stopped if password file doesn't exist.
     218
     219Note that lighttpd doesn't support 'valid-user' in versions prior to 1.3.16.
     220
     221Conditional configuration is also useful for mapping static resources, i.e. serving out images and CSS directly instead of through FastCGI:
     222{{{
     223# Aliasing functionality is needed
     224server.modules += ("mod_alias")
     225
     226# Set up an alias for the static resources
     227alias.url = ("/trac/chrome/common" => "/usr/share/trac/htdocs")
     228
     229# Use negative lookahead, matching all requests that ask for any resource under /trac, EXCEPT in
     230# /trac/chrome/common, and use FastCGI for those
     231$HTTP["url"] =~ "^/trac(?!/chrome/common)" {
     232# Even if you have other fastcgi.server declarations for applications other than Trac, do NOT use += here
     233fastcgi.server = ("/trac" =>
     234                   ("trac" =>
     235                     ("socket" => "/tmp/trac-fastcgi.sock",
     236                      "bin-path" => fcgi_binary,
     237                      "check-local" => "disable",
     238                      "bin-environment" =>
     239                        ("TRAC_ENV" => "/path/to/projenv")
     240                     )
     241                   )
     242                 )
     243}
     244}}}
     245The technique can be easily adapted for use with multiple projects by creating aliases for each of them, and wrapping the fastcgi.server declarations inside conditional configuration blocks.
     246Also there is another way to handle multiple projects and it's to use TRAC_ENV_PARENT_DIR instead of TRAC_ENV and use global auth, let's see an example:
     247{{{
     248#  This is for handling multiple projects
     249  alias.url       = ( "/trac/" => "/path/to/trac/htdocs/" )
     250
     251  fastcgi.server += ("/projects"  =>
     252                      ("trac" =>
     253                        (
     254                          "socket" => "/tmp/trac.sock",
     255                          "bin-path" => fcgi_binary,
     256                          "check-local" => "disable",
     257                          "bin-environment" =>
     258                            ("TRAC_ENV_PARENT_DIR" => "/path/to/parent/dir/of/projects/" )
     259                        )
     260                      )
     261                    )
     262#And here starts the global auth configuration
     263  auth.backend = "htpasswd"
     264  auth.backend.htpasswd.userfile = "/path/to/unique/htpassword/file/trac.htpasswd"
     265  $HTTP["url"] =~ "^/projects/.*/login$" {
     266    auth.require = ("/" =>
     267                     (
     268                       "method"  => "basic",
     269                       "realm"   => "trac",
     270                       "require" => "valid-user"
     271                     )
     272                   )
     273  }
     274}}}
     275
     276Changing date/time format also supported by lighttpd over environment variable LC_TIME
     277{{{
     278fastcgi.server = ("/trac" =>
     279                   ("trac" =>
     280                     ("socket" => "/tmp/trac-fastcgi.sock",
     281                      "bin-path" => fcgi_binary,
     282                      "check-local" => "disable",
     283                      "bin-environment" =>
     284                        ("TRAC_ENV" => "/path/to/projenv",
     285                        "LC_TIME" => "ru_RU")
     286                     )
     287                   )
     288                 )
     289}}}
     290For details about languages specification see [trac:TracFaq TracFaq] question 2.13.
     291
     292Other important information like the [wiki:TracInstall#MappingStaticResources mapping static resources advices] are useful for non-fastcgi specific installation aspects.
     293]
     294
     295Relaunch lighttpd, and browse to `http://yourhost.example.org/trac` to access Trac.
     296
     297Note about running lighttpd with reduced permissions:
     298
     299If nothing else helps and trac.fcgi doesn't start with lighttpd settings `server.username = "www-data"`, `server.groupname = "www-data"`, then in the `bin-environment` section set `PYTHON_EGG_CACHE` to the home directory of `www-data` or some other directory accessible to this account for writing.
     300
     301
     302== Simple !LiteSpeed Configuration ==
     303
     304The FastCGI front-end was developed primarily for use with alternative webservers, such as [http://www.litespeedtech.com/ LiteSpeed].
     305
     306!LiteSpeed web server is an event-driven asynchronous Apache replacement designed from the ground-up to be secure, scalable, and operate with minimal resources. !LiteSpeed can operate directly from an Apache config file and is targeted for business-critical environments.
     307
     308 1. Please make sure you have first have a working install of a Trac project. Test install with “tracd” first.
     309
     310 2. Create a Virtual Host for this setup. From now on we will refer to this vhost as !TracVhost. For this tutorial we will be assuming that your trac project will be accessible via:
     311
     312{{{
     313http://yourdomain.com/trac/
     314}}}
     315
     316 3. Go “!TracVhost → External Apps” tab and create a new “External Application”.
     317
     318{{{
     319Name: MyTracFCGI       
     320Address: uds://tmp/lshttpd/mytracfcgi.sock
     321Max Connections: 10
     322Environment: TRAC_ENV=/fullpathto/mytracproject/ <--- path to root folder of trac project
     323Initial Request Timeout (secs): 30
     324Retry Timeout (secs): 0
     325Persistent Connection   Yes
     326Connection Keepalive Timeout: 30
     327Response Bufferring: No
     328Auto Start: Yes
     329Command: /usr/share/trac/cgi-bin/trac.fcgi  <--- path to trac.fcgi
     330Back Log: 50
     331Instances: 10
     332}}}
     333
     334 4. Optional. If you need to use htpasswd based authentication. Go to “!TracVhost → Security” tab and create a new security “Realm”.
     335
     336{{{
     337DB Type: Password File
     338Realm Name: MyTracUserDB               <--- any name you wish and referenced later
     339User DB Location: /fullpathto/htpasswd <--- path to your htpasswd file
     340}}}
     341
     342If you don’t have a htpasswd file or don’t know how to create the entries within one, go to http://sherylcanter.com/encrypt.php, to generate the user:password combos.
     343
     344 5. Go to “!PythonVhost → Contexts” and create a new “FCGI Context”.
     345
     346{{{
     347URI: /trac/                              <--- URI path to bind to python fcgi app we created   
     348Fast CGI App: [VHost Level] MyTractFCGI  <--- select the trac fcgi extapp we just created
     349Realm: TracUserDB                        <--- only if (4) is set. select realm created in (4)
     350}}}
     351
     352 6. Modify `/fullpathto/mytracproject/conf/trac.ini`
     353
     354{{{
     355#find/set base_rul, url, and link variables
     356base_url = http://yourdomain.com/trac/ <--- base url to generate correct links to
     357url = http://yourdomain.com/trac/      <--- link of project
     358link = http://yourdomain.com/trac/     <--- link of graphic logo
     359}}}
     360
     361 7. Restart !LiteSpeed, “lswsctrl restart”, and access your new Trac project at:
     362
     363{{{
     364http://yourdomain.com/trac/
     365}}}
     366
     367
     368== Simple Nginx Configuration ==
     369
     370Nginx is able to communicate with FastCGI processes, but can not spawn them. So you need to start FastCGI server for Trac separately.
     371
     372 1. Nginx configuration with basic authentication handled by Nginx - confirmed to work on 0.6.32
     373{{{
     374    server {
     375        listen       10.9.8.7:443;
     376        server_name  trac.example;
     377
     378        ssl                  on;
     379        ssl_certificate      /etc/ssl/trac.example.crt;
     380        ssl_certificate_key  /etc/ssl/trac.example.key;
     381
     382        ssl_session_timeout  5m;
     383
     384        ssl_protocols  SSLv2 SSLv3 TLSv1;
     385        ssl_ciphers  ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP;
     386        ssl_prefer_server_ciphers   on;
     387
     388        # (Or ``^/some/prefix/(.*)``.
     389        if ($uri ~ ^/(.*)) {
     390             set $path_info /$1;
     391        }
     392
     393        # it makes sense to serve static resources through Nginx
     394        location /chrome/ {
     395             alias /home/trac/instance/static/htdocs/;
     396        }
     397
     398        # You can copy this whole location to ``location [/some/prefix]/login``
     399        # and remove the auth entries below if you want Trac to enforce
     400        # authorization where appropriate instead of needing to authenticate
     401        # for accessing the whole site.
     402        # (Or ``location /some/prefix``.)
     403        location / {
     404            auth_basic            "trac realm";
     405            auth_basic_user_file /home/trac/htpasswd;
     406
     407            # socket address
     408            fastcgi_pass   unix:/home/trac/run/instance.sock;
     409
     410            # python - wsgi specific
     411            fastcgi_param HTTPS on;
     412
     413            ## WSGI REQUIRED VARIABLES
     414            # WSGI application name - trac instance prefix.
     415            # (Or ``fastcgi_param  SCRIPT_NAME  /some/prefix``.)
     416            fastcgi_param  SCRIPT_NAME        "";
     417            fastcgi_param  PATH_INFO          $path_info;
     418
     419            ## WSGI NEEDED VARIABLES - trac warns about them
     420            fastcgi_param  REQUEST_METHOD     $request_method;
     421            fastcgi_param  SERVER_NAME        $server_name;
     422            fastcgi_param  SERVER_PORT        $server_port;
     423            fastcgi_param  SERVER_PROTOCOL    $server_protocol;
     424            fastcgi_param  QUERY_STRING       $query_string;
     425
     426            # For Nginx authentication to work - do not forget to comment these
     427            # lines if not using Nginx for authentication
     428            fastcgi_param  AUTH_USER          $remote_user;
     429            fastcgi_param  REMOTE_USER        $remote_user;
     430
     431            # for ip to work
     432            fastcgi_param REMOTE_ADDR         $remote_addr;
     433
     434            # For attchments to work
     435            fastcgi_param    CONTENT_TYPE     $content_type;
     436            fastcgi_param    CONTENT_LENGTH   $content_length;
     437        }
     438    }
     439}}}
     440
     441 2. Modified trac.fcgi:
     442
     443{{{
     444#!/usr/bin/env python
     445import os
     446sockaddr = '/home/trac/run/instance.sock'
     447os.environ['TRAC_ENV'] = '/home/trac/instance'
     448
     449try:
     450     from trac.web.main import dispatch_request
     451     import trac.web._fcgi
     452
     453     fcgiserv = trac.web._fcgi.WSGIServer(dispatch_request,
     454          bindAddress = sockaddr, umask = 7)
     455     fcgiserv.run()
     456
     457except SystemExit:
     458    raise
     459except Exception, e:
     460    print 'Content-Type: text/plain\r\n\r\n',
     461    print 'Oops...'
     462    print
     463    print 'Trac detected an internal error:'
     464    print
     465    print e
     466    print
     467    import traceback
     468    import StringIO
     469    tb = StringIO.StringIO()
     470    traceback.print_exc(file=tb)
     471    print tb.getvalue()
     472
     473}}}
     474
     475 3. reload nginx and launch trac.fcgi like that:
     476
     477{{{
     478trac@trac.example ~ $ ./trac-standalone-fcgi.py
     479}}}
     480
     481The above assumes that:
     482 * There is a user named 'trac' for running trac instances and keeping trac environments in its home directory.
     483 * `/home/trac/instance` contains a trac environment
     484 * `/home/trac/htpasswd` contains authentication information
     485 * `/home/trac/run` is owned by the same group the nginx runs under
     486  * and if your system is Linux the `/home/trac/run` has setgid bit set (`chmod g+s run`)
     487  * and patch from ticket #T7239 is applied, or you'll have to fix the socket file permissions every time
     488
     489Unfortunately nginx does not support variable expansion in fastcgi_pass directive.
     490Thus it is not possible to serve multiple trac instances from one server block.
     491
     492If you worry enough about security, run trac instances under separate users.
     493
     494Another way to run trac as a FCGI external application is offered in ticket #T6224
     495
     496----
     497See also:  TracGuide, TracInstall, [wiki:TracModWSGI ModWSGI], [wiki:TracCgi CGI], [wiki:TracModPython ModPython], [trac:TracNginxRecipe TracNginxRecipe]